Sewing machines



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SEWING MACHINES Filed Feb. 8, 1954 5 Sheets-Sheet 4 `lune l2, 1956 o. QUIST SEWING MACHINES Filed Feb. 8, 1954 FIGB 5 Sheets-Sheet 5 United States Patent O SEWING MACHINES Oscar Qnist, Chicago, Ill., assigner to Unicn Special Machine Company, Chicago, lll., a corporation of liliinois Appiication February 8, 1954, Serial No. 408,865

S Claims. (Cl. 112-213) This invention relates to a sewing machine, and more particularly to a loclrstitch sewing machine provided with a needle feed mechanism.

In the commercial use of sewing machines there is an ever growing demand for machines capable of operation at higher speeds. This has imposed serious problems in the provision of mechanisms capable of forming uniform stitches of various types at the speed required by modern demands. Such problems have been accentuated in machines intended for the production of so-called lockstitches. In a machine of this character a rotary hook is usually driven at a speed double the speed of reciprocation of the needle or needles. It has been found difficult in such a machine to provide the required synchronization of the parts to bring about proper feeding of the work and the necessary rapid formation of the stitches.

When such a machine is being used to form a line of stitches or a seam in a plurality of superposed plies of material it is particularly dicult to insure the even advance of all of the plies to form a neat, flat, and uniform seam.

An important object of the present invention has been to provide means capable of reliable operation in advancing several layers or plies of the work a predetermined, variable distance for the proper and uniform formation of stitches, and at the same time operating the stitch forming devices in desired timing relation to the operation of the work feeding devices to bring about correct lockstitch formation and the production of neat, fiat seams.

In attaining the foregoing object, a feature of the present invention involves the provision of relatively simple and compact connections from the rotary drive shafts for driving the work feeding and stitch forming devices, with a minimum of play and of yielding of the parts.

A further feature of the invention is the provision of a novel combination and arrangement of parts, which is of simple construction and reliable in operation, for insuring accurate and uniform advance of multi-ply work when the machine is driven at high speeds. Readily accessible and simple means are also provided for varying the feed stroke, and hence the length of the stitches formed.

For the purpose of insuring accurate and uniform advance of the work in the course of stitch formation the machine contemplated by the invention is provided not only with a four-motion feed dog but also with a novel arrangement for imparting a coordinated needle feed action. The relationship of the various elements of the construction is such that considerably less play and distortion of the several driving connections from the rotary drive shafts takes place than in previously known arrangements.

An important feature of the work advancing mechanism, according to the invention, is the provision of a relatively short rock shaft for imparting the needle feed movements to a frame in which the needle bar is mounted for reciprocation. This rock shaft extends through and is journaled in a wall of the frame which separates the needle head from the hollow, overhanging arm of the rice 2 frame. It is driven by connections within the arm adjacent said wall and is connected with the needle bar carrying frame within the needle head.

Another feature of the needle feed mechanism is the provision of a connection from the rock shaft to the needle bar carrying frame which is arranged to exert a pull on said frame substantially directly in the plane in which the needle bar swings. This eliminates the tendency, present in prior needle feed mechanisms, of imparting a turning moment to the needle bar carrying frame in the course of swinging the latter. In the new construction the needle bar is relatively short, and does not extend into the path of the rocking connections. The needle bar is disposed directly beneath a portion of those connections.

A further feature of the invention is the provision for effective lubrication of the main wear receiving parts of the several driving connections for the work feeding and stitch forming devices.

Other objects, features and advantages of the invention will appear from the detailed description of an illustrative embodiment of the same which will now be given in conjunction with the accompanying drawings, in which:

Fig. 1 is a View, partly in front elevation and partly in longitudinal section, showing a sewing machine embodying the invention;

Fig. 2 is an end elevational view of the machine, as seen from the left in Fig. 1, with the needle head cover plate removed and certain parts broken away;

Fig. 3 is a bottom plan View of the machine with certain cover plates removed and some parts shown in section for clarity of illustration;

Fig. 4 is an enlarged detail view, partly in plan and partly in horizontal section, of the overhanging arm of the machine and shows a portion of the needle feed mechanism;

Fig. S is a vertical sectional view through the overhanging arm of the machine, taken along the line 5 5 of Fig. 4;

Fig. 6 is a detail view, in vertical section, showing the feed rocker assembly as seen from the rear of the machine;

Fig. 7 is an exploded perspective View of the feed bar and related parts of the machine;

Fig. 8 is a detail view, in elevation, of a member of the feed bar assembly;

Fig. 9 is a perspective view of the part shown in Fig. 8; and

Fig. l() is a vertical sectional View taken through the base and the lower portion of the vertical standard of the machine, taken along the line 1tl-1tl of Fig. 1.

The invention has been illustrated as applied to a machine of the general character disclosed in the patent to Reimer, No. 2,643,625, granted June 30, 1953. It embodies, however, in combination with the devices shown in said Reimer patent, the novel needle feed mechanism and other novel features of the invention.

As shown in Fig. l the machine has a main frame comprising a work supporting base 1G, a hollow vertical standard 1li, and a hollow overhanging arm l2 which carries a needle head 13 at its outer end. A partition wall le serves to separate the space within the overhanging arm 12 from that within the needle head, and thus provides two separate enclosures for various parts of the mechanism. A main drive shaft 15 extends longitudinally of the overhanging arm and is joui-nailed adjacent its right end in a bushing 16, carried by the end wall of the vertical standard, and adjacent its left end in a bushing 17, carried by the partition wall 14. At its right, outer end which projects from the vertical standard, the shaft 15 is provided with a combined handwheel and pulley 18 through which power may be supplied to the machine for driving the latter. Shaft 15 extends into the needle head and has secured thereto, within the needle head, a crank member i9 which is connected by a pitman 20 with a needle bar 2 carrying at its lower end a needle 22.. The needle bar is mounted for substantially vertical reciprocation in a rock frame 23 which is pivotally supported by a stud 24 carried by the lower wall of the needle head. Upon rotation of the drive shaft 15 the needle bar will be reciprocated longitudinally of the rock frame 23, in which it is held for-such longitudinal movement by spaced bearing portions 23a and 23b.

To impart a needle feed action to the needle bar and the needle 22, simple and compact connections are provided from the drive shaft l to the upper end of the rock frame 2,3. The latter is provided with an offset, upward extension 25 which carries a pivot screw 26 by means of which one end of a horizontally disposed link 27 is pivotally connected with the rock frame. The opposite end of the link 27 is pivotally connected by means of a screw stud 2.8 with the lower end of an arm 23 secured to a rock shaft 3i). This rock shaft is journalled in a bearing sleeve 31 which is carried by the partition Wall 2.4 and extends from the latter into the needle head enclosure and also into the enclosure within the overhanging arm. At its inner end, within the overhanging arm, the shaft 3i) has secured thereto an arm (Figs. 4 and 5) which is secured to the shaft 36 by means of a split clamping portion having a tightening screw 33. Arm 32 has an elongated, arcuate slot or opening 34 therein arranged to receive a bolt 35. The latter may be adjusted to any desired position along the arcuate slot and may be clamped in desired position by a nut 36. It will be understood that this cooperates with a sleeve 36a surrounding the shank of the bolt 35 and serves to clamp arm 32 between the head of the bolt 35 and the inner end of sleeve 3641. Pivotally mounted on the sleeve 36a is the upper end of a pitman 37 which has a strap portion 38 at its lower end surrounding an eccentric 39 secured to the drive shaft l5. Needle bearing elements 4@ are preferably provided between the strap 3S and eccentric 39. lt will be apparent that through the connections described the shaft fr@ will be rocked upon each revoiution of the shaft l5 to an extent determined by the position of the bolt 35 along the arcuate slot 34. Rocking of the shaft 3@ will in turn impart rocking movements to the rock frame 23, through the connections described, within the needle head.

An important feature of the mechanism just described is the provision of the link 27 in a plane quite close to that in which the needle bar 2l is swung upon the rocking of the rock frame. The arm 29 which operates the link 27 is disposed directly above the upper end of the needle bar, which as best shown in Fig. 2 terminates slightly below the arm 29 when the needle bar is in its.

uppermost position. The arrangement is such as to impart a rocking movement to the frame ...3 and needle bar 2l substantially in the plane of movement of the needle bar. This reduces to a minimum the tendency of the rock frame to bind in relation to its pivot pin 24.

Also, it will be noted that the needle feed mechanism is very compact and employs only a very short rock shaft. This reduces to a minimum any tendency of distortion and also play of the parts. To further minimize the distortion of the parts, as they are operated at high speed, the rock frame 23 is preferably formed of light weight metal such as an aluminum or magnesium alloy.

Directly over the arm 32 and the operating connections therefor, the overhanging arm l2 of the main frame is provided with a cover 4l which is hingedly mounted on the frame, as indicated at 42. A latch 43 serves to retain the cover in closed position when the machine is in operation. Opening of the cover provides ready access to the arm 32 and its driving connections for appropriate adjustment of the bolt 35 along the arcuate slot 34. On the upper surface of the arm 32 there is preferably provided a series of markings and designations 44, which in cooperation with a line 44a formed in the top of the pitman 38 serves to indicate the feed stroke for which the parts have been adjusted. The designations 44 may be in accordance with the stitch length designations commonly employed in relation to the feed stroke adjusting means for the feed dog.

The work supporting base lit) of the machine is provided with a rotary drive shaft 45, which is journalled in a bearing sleeve 46 in a downward extension of the vertical standard and in a bearing sleeve 47 adjacent the left end of the shaft. Various intermediate bearings may also be provided. Shaft is driven in synchronism with shaft 15 through a gear 43 secured to shaft 15, an idler gear 49 freely rotatable about a fixed shaft in the vertical standard, and a gear 50 secured to the shaft 45 adjacent its right hand end.

At an intermediate point the base 1li) is provided with a downwardly extending housing 51 through which the shaft 45 extends. Within this housing there is secured to the shaft 45 a gear 52 which meshes with a pinion 53 secured to a hook shaft 54 journalled in bearing sleeves 55 and 56. At its outer or left end, the hook shaft carries a rotary hook 57 which is arranged to cooperate with the needle 22 to form lock stitches. Gearing 52, 53 is such that the rotary component of the rotary hook is driven at double the angular speed of the shafts 15 and 45.

Cooperating with the needle in advancing the work is a four motion feed dog 60 (Fig. 2) which may be constructed and operated in a manner similar to the feed mechanism disclosed in the above mentioned patent to Reimer. The feed dog has toothed portions which pass upwardly through suitable elongated openings in a throat plate 61 provided in the work supporting surface of the machine. It is given lifting and lowering movements and also longitudinal feed and return movements in relation to the throat plate. The feed dog is carried by a member 62 to which it is secured in any suitable way, preferably in a manner permitting slight relative longitudinal adjustment, as explained in the Reimer patent. Member 62 has a downwardly extending shank 62a having a vertically elongated opening 63 cooperating with the shank of a screw 64 by which the member is secured to a feed bar 65. The shank 62a tits snugly within a channel 66 provided in an element 67 carried by the feed bar 65,. This element is secured to the feed bar, in part by the screw 64 which passes through an opening 68 in element 67 and is threaded into an opening 69 in the feed bar. Another screw 70 passes through an opening 7l in element 67 and is threaded into an opening 72 in the feed bar. As best shown in Fig. 8 the opening 'if has substantial clearance in relation to the shank of the screw 7() and thus enables angling of the element 67 in relation to the feed bar 65. When adjusted to the proper angular position the two screws 64 and 70 may be tightened and the element thus rmly secured to the feed bar. Such angling of the element on the feed bar makes possible the tilting of the feed dog 6i) either downwardly or upwardly, from front to rear, to provide the best feeding action for various types of work. A screw 73 cooperating with a threaded opening 74 in the element 67 is arranged to have its enlarged head cooperate with the lower end of the shank 62a and thus insure retention of the member 62 at the proper elevation.

Feed bar 65 is provided with a hub portion 75 at its rearward end which receives a pivot pin 76 (Fig. 6). This pin is secured against movement in relation to the hub 75 by means of a set screw 75a (Fig. 7). The pin 76 cooperates with spaced bearings provided in an upwardly extending feed rocker 77 journalled by means of a shaft 77a in suitable bearings in the frame. Rocking movements are imparted to the feed rocker by connections frorn the rotary drive shaft 45. For this purpose a pin 78 carried by the feed rocker provides a pivotal connection with a sleeve 79 at the outer end of a pitman 80 (Fig. 3); the latter has a strap 81 at its inner end which cooperates with an adjustable eccentric unit 82 carried by the shaft 4S. This adjustable eccentric unit may be of the same character as that disclosed in the above mentioned Reimer patent. The extent of eccentricity of the eccentric may be varied by causing a nger 83 to engage a notch or recess in the innermost of a pair of telescoping eccentrics and to hold this inner eccentric against turning, while the shaft 4S together with the outermost eccentric of the telescoping pair is turned the desired angular distance by turning of the handwheel 18. Finger 83 may be operated to bring about such adjustment by devices of the character disclosed in said Reimer patent. For this purpose the finger is secured to a rock shaft 84 (Figs. 3 and l0) which extends from the region of the finger over to the vertical standard and within the latter is provided with an arm 85. This arm is urged by a spring 85a against the inner end of a plunger 86, slidably mounted in the frame and arranged for manual op eration by depressing a button S7' at its outer end. When this button is pressed inwardly the shaft 84 will be rocked and the finger 83 will be carried into engagement with the detaining notch in the inner eccentric member to hold it against rotation, as explained. The handwheel 18 may be turned in either direction to bring about the desired adjustment. An indication of the adjustment is afforded by a disk 8S secured to the shaft 45 carrying indicia that are visible through an opening 89 through the work supporting surface of the base l0. These indicia correspond with those on the arm 32 identified with the needle feed mechanism.

Cooperating with the feed dog, to assist in advancing the work, is a presser foot 90 carried by a presser bar 91 which is urged downwardly under suitable pressure by a spring 92. Customary means may be provided for lifting the presser bar either manually or under knee or foot control to permit the introduction and removal of work.

Referring to Fig. i, it will be noted that the overhanging arm l2 has its lower wall inclined downwardly slightly toward the left to provide an oil reservoir 93 adapted to retain lubricant which is dispersed by the operation of the eccentric 39 and pitman 37. Effective lubrication of the needle feed driving connections is thus brought about. At the same time the parts within the needle head are protected against excessive lubrication which may soil the stitching threads. This is accomplished by the separation of the needle head enclosure from the enclosure within the hollow arm by means of the partition wall 14. The various wear receiving surfaces within the vertical standard are lubricated from a body of lubricant maintained within a reservoir 94 at the base of the vertical standard. Gear 50 serves to create a lubricant mist from the lubricant in this reservoir to accomplish this result, and some of this mist will be carried into the overhanging arm and deposited in the reservoir 93. Some of it may reach the needle feed operating devices shown in Fig. 5 before being deposited in reservoir 93. Whenever desired the lubricant in the latter reservoir may be supplemented by simply lifting the cover 4l and introducing an appropriate amount of lubricant, Any excess lubricant which may collect in the reservoir 93 will drain along the interior of the hollow arm and be delivered to the reservoir 94.

Other customary devices will be included in the machine, as, for example, thread supplying, tensioning, and take up means, but since these form no part of the present invention it is believed unnecessary to describe them.

While an illustrative form of the invention has been disclosed in considerable detail, it should be understood that various modifications may be made Without departing from the general principles and scope of the invention.

What is claimed is:

l. In a sewing machine having a frame provided with a work supporting base, a hollow standard, a hollow overhanging arm, and a needle head at the end of said arm, a partition wall at the end of said arm adjacent said needle head serving to provide separated enclosures for said head and arm, a rotary drive shaft extending longitudinally of said arm and through said wall into said needle head, a rock frame mounted in said needle head upon a fixed pivot, a needle bar mounted for reciprocation in said rock frame and carrying a needle at its lower end, connections in said needle head from said rotary shaft to said needle bar for reciprocating the latter, a short rock shaft journaled in said wall and extending through the same, connections with said hollow arm adjacent said wall from said rotary shaft to said rock shaft for rocking the latter, and connections within said needle head from said rock shaft to said rock frame for rocking the latter and thereby imparting a needle feed movement to said needle bar, said last mentioned connections comprising a bodily movable link disposed and movable in a vertical plane transverse to the axis of said rock shaft and substantially passing through the vertical center line of said rock frame.

2. In a sewing machine having a frame provided with a work supporting base, a hollow standard, a hollow overhanging arm, and a needle head at the end of said arm, a partition wall at the end of said arm adjacent said needle head ser-ving to provide separated enclosures for said head and arm, means for creating a lubricant mist within said arm, a rotary drive shaft extending longitudinally of said arm and through said wall into said needle head, a rock frame mounted in said needle head upon a fixed pivot, a needle bar mounted for reciprocation in said rock frame and carrying a needle at its lower end, connections in said needle head from said rotary shaft to said needle bar for reciprocating the latter, a short rock shaft journalled in said wall and extending through the same, said rock shaft having its axis in substantially the same vertical plane as the axis of said rotary shaft connections within said hollow arm adjacent said wall from said rotary shaft to said rock shaft for rocking the latter, and connections within said needle head from said rock shaft to said rock frame for rocking the latter and thereby imparting a needle feed movement to said needle bar.

3. ln a sewing machine having a frame provided with a Work supporting base, a hollow standard, a hollow overhanging arm, and a needle head at the end of said arm, a partition wall at the end of said arm adjacent said needle head serving to provide separated enclosures for said head and arm, a rotary drive shaft extending longitudinally of said arm and through said Wall into said needle head, a rock frame mounted in said needle head for movement about a fixed axis, a needle bar mounted for reciprocation in said rock frame and carrying a needle at its lower end, connections in said needle head from said rotary shaft to said needle bar for reciprocating the latter, a short rock shaft journalled in said wall and extending through the same, said rock shaft having its axis in substantially the same vertical plane as the axis of said rotary shaft connections within said hollow arm adjacent said wall from said rotary shaft to said rock shaft for rocking the latter, and connections within said needle head from said rock shaft to said rock frame for rocking the latter and thereby imparting a needle feed movement to said needle bar, said last mentioned connections including a link connected with said rock frame and movable bodily substantially in the vertical plane in which said needle bar is swung.

4. ln a sewing machine having a frame provided with a work supporting base, a hollow standard, a hollow overhanging arm, and a needle head at the end of said arm, a partition Wall at the end of said arm adjacent sai-d needle head serving to provide separated enclosures for said head and arm, a rotary drive shaft extending longitudinally of said arm and through said wall into said needle head, a rock frame mounted in said needle head for movement about a fixed axis, a needle bar mounted for substantially vertical reciprocation in said rock frame in rear of the vertical plane containing the axis of said fixed pivot and carrying a needle at its lower end, connections in said needle head from said rotary shaft to said needle bar for reciprocating the latter, a short rock shaft journalled in said wall and extending through the same, connections within said hollow arm adjacent said wall from said rotary shaft to said rock shaft for rocking the latter, said last mentioned connections including an eccentric on said rotary shaft, an arm on said rock shaft having an elongated opening, and a pitman cooperating with said eccentric and pivotally connected with said arm along said opening, the axis of said pivotal connection being adjustable along said opening, said hollow arm of the machine frame having a normally closed opening and a movable cover therefor for providing access to said pivotal connection for adjusting the same, and connections within said needle head from said rock shaft to said rock frame for rocking the latter and thereby imparting a needle feed movement to said needle bar, Said last mentioned connections including a bodily movable link pivotally connected with said rock frame along an axis substantially in the vertical plane containing the axis about which said frame is rocked.

5. In a sewing machine having a frame provided With a work supporting base, a hollow standard, a hollow overhanging arm, and a needle head at the end of said arm, a partition wall at the end of said arm adjacent said needle head serving to provide separated enclosures for said head and arm, a rotary drive shaft extending longitudinally of said arm and through said wall into said needle head, a rock frame mounted .in said needle head for movement about a xed axis, a needle bar mounted for substantially vertical reciprocation in said rock frame in rear of the vertical plane containing the axis of said xed pivot and carrying a needle at its lower end, connections in said needle head from said rotary shaft to said needle bar for reciprocating the latter, a short rock shaft journalled in said wall and extending through the same, connections within said hollow arm adjacent said wall from said rotary shaft to said rock shaft for rocking the latter, said last mentioned connections .including an eccentric on said rotary shaft, an arm on said rock shaft having an elongated opening, and a pitman cooperating with sai-d eccentric and pivotally connected with said arm along said opening, the axis of said pivotal connection being adjustable along said opening, said hollow arm of the machine frame having a normally closed opening and a movable cover therefor for providing access to said pivotal connection for adjusting the same, coordinated means on sai-d pitman and said arm on said rock shaft for indicating the adjustment of said pivotal connection, and connections within said needle head from said rock shaft to said rock frame for rocking the latter and thereby imparting a needle feed movement to said needle bar.

6. In a sewing machine having a frame provided with a work supporting base, a hollow standard, a hollow overhanging arm, and a needle head at the end of said arm, a partition wall at the end of said arm adjacent said needle head serving to provide separated enclosures for said head and arm, a rotary drive shaft extending longitudinally of said arm and through said wall into Said needle head, a rock frame formed of lightweight metal pivotally mounted in said needle head about a xed axis adjacent the bottom of said needle head, a needle bar mounted for reciprocation in said rock frame and carrying a needle at its lower end, connections in said needle head from said rotary shaft to said needle bar for reciprocating the latter, a short rock shaft journalled in said wall and extending through the same, connections within said hollow arm adjacent said wall from said rotary shaft to said rock shaft for rocking the latter, and connections within said needle head from said rock shaft to said rock frame for rocking the latter and thereby imparting a needle feed movement to said needle bar, said last mentioned connections including a link pivotally connected with said rock frame and movable bodily substantially in the plane in which said needle bar is swung an-d including a part disposed directly over the top of said needle bar.

7. In a sewing machine having a frame provided with a work supporting base, a hollow standard, a hollow overhanging arm, and a needle head at the end of said arm, a partition wall at the end of said arm adjacent said needle head serving to provide separated enclosures for said head and arm, a rotary drive shaft extending longitudinally of said arm and through said wall into said needle head, a rotary shaft extending longitudinally of sai-d base, means interconnecting said rotary shafts for rotation in unison, a rock frame pivotally mounted in said needle head on a fixed pivot adjacent the lower end of said needle head, a needle bar mounted for substantially vertical reciprocation in said rock frame along a path directly in rear of said fixed pivot and carrying a needle at its lower end, connections in said needle head from said rst mentioned rotary shaft to said needle bar for reciprocating the latter, a short rock shaft journalled in said wall and extending through the same, connections in said hollow arm adjacent said Wall from said rotary shaft in said arm to said rock shaft for rocking the latter, connections within said needle head from said rock shaft to said rock frame for rocking the latter and thereby imparting a needle feed movement to said needle bar, a horizontal axis rotary hook in said base arranged to cooperate with said needle to form lockstitches, and connections from said rotary shaft in the base to said rotary hook for driving the latter.

8. In a sewing machine having a frame provided with a work supporting base, a hollow standard, a hollow overhanging arm, and a needle head at the end of said arm, a partition wall at the end of said arm adjacent said needle head serving to provide separated enclosures for said head and arm, a rotary drive shaft extending longitudinally of said arm and through said Wall .into said needle head, a rock frame mounted in said needle head, a needle bar mounted for reciprocation in said rock frame and carrying a needle at its lower end, connections in' said needle head from said rotary shaft to said needle bar for reciprocating the latter, a short rock shaft journalled in said wall and extending through the same, connections within said hollow arm adjacent said wall from said rotary shaft to said rock shaft for rocking the latter, a lubricant reservoir within said overhanging arm in the region of said last mentioned connections and adapted to carry lubricant for engagement and dispersal by said connections, and connections within said needle head from said rock shaft to said rock frame for rocking the latter and thereby imparting a needle feed movement to said needle bar.

References Cited in the file of this patent UNITED STATES PATENTS 1,001,809 Brown Aug. 29, 1911 2,292,257 Zeier Aug. 4, 1942 2,329,484 Quist Sept. 14, 1943 2,329,681 Zeier Sept. 14, 1943 2,643,625 Reimer June 30, 1953 

